## Quick Reference

(in 3-dimensional space)

The distance from the point *P* to the plane *p* is the shortest distance between *P* and a point in *p*, and is equal to |*PN*|, where *N* is the point in *p* such that the line *PN* is normal to *p*. If *P* has coordinates (*x*_{1}, *y*_{1}, *z*_{1}) and *p* has equation *ax*+*by*+*cz*+*d*=0, the distance from *P* to *p* is equal to

where |*ax*_{1}+*by*_{1}+*cz*_{1}+*d*| is the absolute value of *ax*_{1}+*by*_{1}+*cz*_{1}+*d*.

*Subjects:*
Mathematics.

## Related content in Oxford Index

##### Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.